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Sourcecode: wacom-tools version File versions

evdev.c

/*
 * $Id: evdev.c,v 1.2 2004/02/25 18:32:18 pingc Exp $
 *
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 *
 *  Event char devices, giving access to raw input device events.
 *
 *  Sponsored by SuSE
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@suse.cz>, or by paper mail:
 * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
 */

#include <linux/autoconf.h>
#if defined(CONFIG_MODVERSIONS) && !defined(MODVERSIONS)
#   define MODVERSIONS
#endif

#ifdef MODVERSIONS
#include <linux/modversions.h>
#endif

#define EVDEV_MINOR_BASE      64
#define EVDEV_MINORS          32
#define EVDEV_BUFFER_SIZE     64

#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/smp_lock.h>

struct evdev {
      int exist;
      int open;
      int minor;
      struct input_handle handle;
      wait_queue_head_t wait;
      devfs_handle_t devfs;
      struct evdev_list *list;
};

struct evdev_list {
      struct input_event buffer[EVDEV_BUFFER_SIZE];
      int head;
      int tail;
      struct fasync_struct *fasync;
      struct evdev *evdev;
      struct evdev_list *next;
};

static struct evdev *evdev_table[EVDEV_MINORS] = { NULL, /* ... */ };

static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
{
      struct evdev *evdev = handle->private;
      struct evdev_list *list = evdev->list;

      while (list) {

            do_gettimeofday(&list->buffer[list->head].time);
            list->buffer[list->head].type = type;
            list->buffer[list->head].code = code;
            list->buffer[list->head].value = value;
            list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);

            kill_fasync(&list->fasync, SIGIO, POLL_IN);

            list = list->next;
      }

      wake_up_interruptible(&evdev->wait);
}

static int evdev_fasync(int fd, struct file *file, int on)
{
      int retval;
      struct evdev_list *list = file->private_data;
      retval = fasync_helper(fd, file, on, &list->fasync);
      return retval < 0 ? retval : 0;
}

static int evdev_release(struct inode * inode, struct file * file)
{
      struct evdev_list *list = file->private_data;
      struct evdev_list **listptr;

      lock_kernel();
      listptr = &list->evdev->list;
      evdev_fasync(-1, file, 0);

      while (*listptr && (*listptr != list))
            listptr = &((*listptr)->next);
      *listptr = (*listptr)->next;

      if (!--list->evdev->open) {
            if (list->evdev->exist) {
                  input_close_device(&list->evdev->handle);
            } else {
                  input_unregister_minor(list->evdev->devfs);
                  evdev_table[list->evdev->minor] = NULL;
                  kfree(list->evdev);
            }
      }

      kfree(list);
      unlock_kernel();

      return 0;
}

static int evdev_open(struct inode * inode, struct file * file)
{
      struct evdev_list *list;
      int i = MINOR(inode->i_rdev) - EVDEV_MINOR_BASE;

      if (i >= EVDEV_MINORS || !evdev_table[i])
            return -ENODEV;

      if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
            return -ENOMEM;
      memset(list, 0, sizeof(struct evdev_list));

      list->evdev = evdev_table[i];
      list->next = evdev_table[i]->list;
      evdev_table[i]->list = list;

      file->private_data = list;

      if (!list->evdev->open++)
            if (list->evdev->exist)
                  input_open_device(&list->evdev->handle);

      return 0;
}

static ssize_t evdev_write(struct file * file, const char * buffer, size_t count, loff_t *ppos)
{
      struct evdev_list *list = file->private_data;
      struct input_event event;
      int retval = 0;

      while (retval < count) {

            if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
                  return -EFAULT;
            input_event(list->evdev->handle.dev, event.type, event.code, event.value);
            retval += sizeof(struct input_event);
      }

      return retval;
}

static ssize_t evdev_read(struct file * file, char * buffer, size_t count, loff_t *ppos)
{
      DECLARE_WAITQUEUE(wait, current);
      struct evdev_list *list = file->private_data;
      int retval = 0;

      if (list->head == list->tail) {

            add_wait_queue(&list->evdev->wait, &wait);
            current->state = TASK_INTERRUPTIBLE;

            while (list->head == list->tail) {

                  if (!list->evdev->exist) {
                        retval = -ENODEV;
                        break;
                  }
                  if (file->f_flags & O_NONBLOCK) {
                        retval = -EAGAIN;
                        break;
                  }
                  if (signal_pending(current)) {
                        retval = -ERESTARTSYS;
                        break;
                  }

                  schedule();
            }

            current->state = TASK_RUNNING;
            remove_wait_queue(&list->evdev->wait, &wait);
      }

      if (retval)
            return retval;

      while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
            if (copy_to_user(buffer + retval, list->buffer + list->tail,
                   sizeof(struct input_event))) return -EFAULT;
            list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
            retval += sizeof(struct input_event);
      }

      return retval;
}

/* No kernel lock - fine */
static unsigned int evdev_poll(struct file *file, poll_table *wait)
{
      struct evdev_list *list = file->private_data;
      poll_wait(file, &list->evdev->wait, wait);
      if (list->head != list->tail)
            return POLLIN | POLLRDNORM;
      return 0;
}

static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
      struct evdev_list *list = file->private_data;
      struct evdev *evdev = list->evdev;
      struct input_dev *dev = evdev->handle.dev;
      int retval;

      if (!evdev->exist)
            return -ENODEV;

      switch (cmd) {

            case EVIOCGVERSION:
                  return put_user(EV_VERSION, (int *) arg);

            case EVIOCGID:
                  if ((retval = put_user(dev->idbus,     ((short *) arg) + 0))) return retval;
                  if ((retval = put_user(dev->idvendor,  ((short *) arg) + 1))) return retval;
                  if ((retval = put_user(dev->idproduct, ((short *) arg) + 2))) return retval;
                  if ((retval = put_user(dev->idversion, ((short *) arg) + 3))) return retval;
                  return 0;

            case EVIOCSFF:
                  if (dev->upload_effect) {
                        struct ff_effect effect;
                        int err;

                        if (copy_from_user((void*)(&effect), (void*)arg, sizeof(effect))) {
                              return -EINVAL;
                        }
                        err = dev->upload_effect(dev, &effect);
                        if (put_user(effect.id, &(((struct ff_effect*)arg)->id))) {
                              return -EINVAL;
                        }
                        return err;
                  }
                  else return -ENOSYS;

            case EVIOCRMFF:
                  if (dev->erase_effect) {
                        return dev->erase_effect(dev, (int)arg);
                  }
                  else return -ENOSYS;

            case EVIOCGEFFECTS:
                  put_user(dev->ff_effects_max, (int*) arg);
                  return 0;

            default:

                  if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
                        return -EINVAL;

                  if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {

                        long *bits;
                        int len;

                        switch (_IOC_NR(cmd) & EV_MAX) {
                              case      0: bits = dev->evbit;  len = EV_MAX;  break;
                              case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
                              case EV_REL: bits = dev->relbit; len = REL_MAX; break;
                              case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
                              case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
                              case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
                              case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
                              default: return -EINVAL;
                        }
                        len = NBITS(len) * sizeof(long);
                        if (len > _IOC_SIZE(cmd)) {
                              printk(KERN_WARNING "evdev.c: Truncating bitfield length from %d to %d\n",
                                    len, _IOC_SIZE(cmd));
                              len = _IOC_SIZE(cmd);
                        }
                        return copy_to_user((char *) arg, bits, len) ? -EFAULT : len;
                  }

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
                        int len;
                        if (!dev->name) return 0;
                        len = strlen(dev->name) + 1;
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->name, len) ? -EFAULT : len;
                  }

                  if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {

                        int t = _IOC_NR(cmd) & ABS_MAX;

                        if ((retval = put_user(dev->abs[t],     ((int *) arg) + 0))) return retval;
                        if ((retval = put_user(dev->absmin[t],  ((int *) arg) + 1))) return retval;
                        if ((retval = put_user(dev->absmax[t],  ((int *) arg) + 2))) return retval;
                        if ((retval = put_user(dev->absfuzz[t], ((int *) arg) + 3))) return retval;
                        if ((retval = put_user(dev->absflat[t], ((int *) arg) + 4))) return retval;

                        return 0;
                  }
      }
      return -EINVAL;
}

static struct file_operations evdev_fops = {
      owner:            THIS_MODULE,
      read:       evdev_read,
      write:            evdev_write,
      poll:       evdev_poll,
      open:       evdev_open,
      release:    evdev_release,
      ioctl:            evdev_ioctl,
      fasync:           evdev_fasync,
};

static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev)
{
      struct evdev *evdev;
      int minor;

      for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++)
      {

            if (!evdev_table[minor]->exist && evdev_table[minor]->open) /* reuse */
            {
                  evdev = evdev_table[minor];
                  evdev->handle.dev = dev;
                  evdev->handle.handler = handler;
                  evdev->handle.private = evdev; /* should already be */
                  evdev->exist = 1;
                  printk(KERN_INFO "evdev: reusing event%d for input%d\n", minor, dev->number);
                  input_open_device(&evdev->handle);
                  wake_up_interruptible(&evdev->wait);
                  return &evdev->handle;
            }
      }
      if (minor == EVDEV_MINORS) {
            printk(KERN_ERR "evdev: no more free evdev devices\n");
            return NULL;
      }

      if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
            return NULL;
      memset(evdev, 0, sizeof(struct evdev));

      init_waitqueue_head(&evdev->wait);

      evdev->minor = minor;
      evdev_table[minor] = evdev;

      evdev->handle.dev = dev;
      evdev->handle.handler = handler;
      evdev->handle.private = evdev;

      evdev->exist = 1;

      evdev->devfs = input_register_minor("event%d", minor, EVDEV_MINOR_BASE);

//    printk(KERN_INFO "event%d: Event device for input%d\n", minor, dev->number);

      return &evdev->handle;
}

static void evdev_disconnect(struct input_handle *handle)
{
      struct evdev *evdev = handle->private;

      evdev->exist = 0;

      if (evdev->open) {
            input_close_device(handle);
            wake_up_interruptible(&evdev->wait);
      } else {
            input_unregister_minor(evdev->devfs);
            evdev_table[evdev->minor] = NULL;
            kfree(evdev);
      }
}

static struct input_handler evdev_handler = {
      event:            evdev_event,
      connect:    evdev_connect,
      disconnect: evdev_disconnect,
      fops:       &evdev_fops,
      minor:            EVDEV_MINOR_BASE,
};

static int __init evdev_init(void)
{
      input_register_handler(&evdev_handler);
      return 0;
}

static void __exit evdev_exit(void)
{
      input_unregister_handler(&evdev_handler);
}

module_init(evdev_init);
module_exit(evdev_exit);

MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION("Event character device driver");
MODULE_LICENSE("GPL");


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